Software will be developed to visualize the estimated extent and time course of activity within the brain from an array of MEG sensors placed over the head. The software will include both a Windows-based turnkey package for analysis and display, and a toolkit/subroutine library to aid researchers in developing their own analysis applications. This requires the implementation and validation of algorithms to identify multiple sources and estimate their locations and time course. Preliminary results suggest the feasibility of the approach, which uses novel estimation techniques, not currently available for the analysis of magnetic recordings. Methods will be verified using phantoms and physiological data. Potential applications of these methods include both research and eventual clinical uses, such as the localization and lateralization of language function, monitoring of stroke and psychiatric disorders, and the estimation of cortical activity during sensory evoked responses and cognitive activity.